Hasse Abrahamsson och Simeon Antov, forskare vid Sahlgrenska Universitetssjukhuset, utvecklade principen för Transit-Pelletsmetoden™. Transit-Pelletsmetoden™ är internationellt välkänd som Abrahamsson Method. Nedan presenteras exempel på betydelsefulla studier.

1. *Abrahamsson H, Antov S, Bosaeus I. Gastrointestinal and colonic segmental transit time evaluated by a single abdominal X-ray in healthy subjects and constipated patients. Scand J Gastroenterol 1988, 23 (suppl 152), 72-80
2. *Abrahamsson H, Antov S. Accuracy in assessment of colonic transit time with particles: how many markers should be used? Neurogastroenterol Motil. 2010;22:1164-69
3. *Bohlin J, Dahlin E, Dreja J, Roth B, Ekberg O, Ohlsson B. Longer colonic transit time is associated with laxative and drug use, lifestyle factors, and symptoms of constipation. Acta Radiologica Open. 2018;7(10):1-9
4. *Tsimogiannis KE, Karlbom U, Lundin E, Graf W. Long-term outcome after segmental colonic resection for slow transit constipation. Int J Colorectal Dis 2019, 34(6):1013-1019.
5. **Sadik R, Abrahamsson H, Stotzer PO. Gender differences in gut transit shown with a newly developed radiological procedure. Scand J Gastroenterol 2003;38:36-42.
6. **Sadik R, Abrahamsson H, Björnsson E, Gunnarsdottir A, Stotzer PO. Etiology of portal hypertension may influence gastrointestinal transit. Scand J Gastroenterol. 2003 Oct;38(10):1039-44.
7. **Sadik R, Abrahamsson H, Kilander A, Stotzer PO. Gut transit in celiac disease: delay of small bowel transit and acceleration after dietary treatment. Am J Gastroenterol. 2004 Dec;99(12):2429-36.
8. **Sadik R, Abrahamsson H, Ung KA, et al. Accelerated regional bowel transit and overweight shown in idiopathic bile acid malabsorption. Am J Gastroenterol 2004;99:711-718.
9. **Sadik R, Stotzer PO, Simrén M, Abrahamsson H. Gastrointestinal transit abnormalites are frequently detected in patients with unexplained GI symptoms at a tertiary centre. Neurogastroenterol Motil. 2008;20:197-205.
10. **Abrahamsson H, Östlund-Lindqvist AM, Nilsson R, Simrén M, Gillberg PG. Altered bile acid metabolism patients with constipation-predominant irritable bowel syndrome and functional constipation. Scand J Gastroenterol. 2008;43(12):1483-8.
11. **Sadik R, Björnsson E, Simrén M. The relationship between symptoms, body mass index, gastrointestinal transit and stool frequency in patients with irritable bowel syndrome. Eur J Gastroenterol Hepatol. 2010 Jan;22(1):102-8.
12. **Simren M, Bajor A, Gillberg PG, Rudling M, Abrahamsson H. Randomised clinical trial: The ileal bile acid transporter inhibitor A3309 vs. placebo in patients with chronic idiopathic constipation–a double-blind study. Aliment Pharmacol Ther. 2011;34(1):41-50.
13. **Strid H, Simrén M, Störsrud S, Stotzer PO, Sadik R. Effect of heavy exercise on gastrointestinal transit in endurance athletes. Scand J Gastroenterol. 2011 Jun;46(6):673-7.
14. **Törnblom H, Van Oudenhove L, Sadik R, Abrahamsson H, Tack J, Simrén M. Colonic transit time and IBS symptoms: what’s the link? Am J Gastroenterol. 2012 May;107(5):754-60.
15. **Lindfors P, Törnblom H, Sadik R, Björnsson ES, Abrahamsson H, Simrén M. Effects on gastrointestinal transit and antroduodenojejunal manometry after gut-directed hypnotherapy in irritable bowel syndrome. IBS Scand J Gastroenterol. 2012 Dec;47(12):1480-7.
16. **Stotzer, P.O., Abrahamsson, H., Bajor, A., et al. Effect of Cholestyramine on Gastrointestinal Transit in Patients with Idiopathic Bile Acid Diarrhea: A Prospective, Open-Label Study. Ashdin Publishing: Neuroenterology Vol. 2, 2013.
17. **Tucker R, Ryan S, Hayee Hussain B, Bjarnason et al. Distinctive Pathophysiology Underlying Constipation in Parkinson’s Disease: Implications for Cognitive Inefficiency. J. Clin. Med. 2020, 9(6), 1916: 1-14

* Studier med originalversion, sista markördos 24 timmar före röntgen
** Studier med nuvarande version, sista markördos 12 timmar före röntgen

Nedan presenteras exempel på betydelsefulla studier, barn och ungdomar

I jämförelse med andra metoder konkluderade Wagener et al (2004) och Vande Velde et al (2013) att Abrahamsson Method är den lämpligaste metoden vid kolontransitundersökning för barn och tonåringar.

1. Wagener K.R, Shankar R.R, Turnock G.L. Colonic Transit Time – What Is Normal? Journal of Pediatric Surgery. 2004:Vol 39, No 2, pp166-169.
2. Velde V, Notebaert V, Meersschaut N. Colon transit time in healthy children and adolescent. Int J Colorectal Dis. 2014:28:1721-1724.
3. Rintala R.J, Marttinen K, Virkola M, Rasanen C, Baillie C, Lindahl H. Segmental Colonic Motility in Patients With Anorectal Malformations. Journal of Pediatric Surgery. 1997: Vol 32, No 3, pp 453-456.
4. Baillie C.T, Kenny S.E, Rintala J.M, Lloyd D.A. Long-Term Outcome and Colonic Motility After the Duhamel Procedure for Hirschsprung’s Disease. Journal of Pediatric Surgery. 1999:Vol 34, No2, pp325-329.